Stretcher frames for stretching a stretchable carrier are generally known. Standard stretcher frames consist of a stretcher frame made up of key bars or stretcher bars of which the diagonal ends of the stretcher bars are provided with a connecting element and whereby the connecting element is arranged in such a way that this may be inserted in a groove in the diagonal end of the connecting stretcher bar. An often occurring problem when stretching a stretchable carrier, such as a painter's canvas, on a stretcher frame, is that during the drying of the materials applied to the carrier such as ink or paint, or over time, the tension of the carrier changes. By placing keys in the corners of the stretcher frame the key bars in the corners can be moved slightly outward in order to properly re-tension the carrier.
A disadvantage of these standard stretcher frames is that the consumer and the stretcher maker have no flexibility for producing the stretcher frames to size. After all, the dimensions of standard stretcher frames are determined during the production of the stretcher bars themselves, not when making the stretcher frame. Another disadvantage is that the stretcher bars such as those used in standard stretcher frames have a limited flexibility at the corners of the stretcher frame for re-tensioning the carrier after this has been fixed to the stretcher frame for some time.